STOCK BASED COMPENSATION PLANS - Employee Stock Purchase Plan (Details) - USD ($)	1 Months Ended	9 Months Ended
	May 31, 2018	Sep. 30, 2019	Sep. 30, 2018
STOCK-BASED COMPENSATION PLANS.
Common stock initially authorized for issuance under the ESPP, Shares	1,000,000
Maximum contribution from employees	$ 25,000
Shares of common stock purchased under the ESPP		4,355	0
Expense recorded related to ESPP		$ 0	$ 0